Compounded oil



Patented Aug. 19, 1941 COMPOUNDED OIL John T. Rutherford and Robert J.Miller, Berkeley, Calm, assignors to Standard Oil Company of California,San Francisco, Call, a corpora- 1 tion of Delaware No Drawing.Application May-c, i939,

\ Serial No. 272.155

24 Claims. (01. 252'-s9) This invention relates to a new andmsel'ulcomposition of matter and involves a composition comprising ahydrocarbon, such as a viscous hydrocarbon oil, and an alkaline earthmetal salt of sulfur-containing substituted acids of phosphorus.

The production of improved hydrocarbon oils, and particularly oflubricating oils having desired characteristics, has been the subject ofextensive and oxidize when subjected to high temperatures.

This deterioration is evidencedby the deposition of adhesive deposits onhot metal surfaces over which the hydrocarbon oil may flow. It isimportant that resistance to such deterioration be imparted tohydrocarbon oils, particularly to lubricating oils, in order that suchcompositions may be relatively free from the. tendency to form suchdeposits even under high temperatures and severe operating conditions. Adirect result or this type of deterioration during lubrication of intemal combustion engines. such as engines of the Diesel type, is thetendency of the oil to cause or permit the sticking of piston rings.

The crankcase lubricant in internal combustion engines is subjected toextremely severe operating conditions and in engines of the Diesel typethe lubricant encounters in the piston ring zone temperatures of fromapproximately 425 to 650 F. and pressures from the oxidizing combustiongases as high as 750 to 1150 lbs. per sq. in. Addition agents whichrender hydrocarbon oils resistant to deterioration by heat at hightemperature levels in the order of those above mentioned usually impartto the oil the ability to inhibit piston ring sticking in internalcombustion engines and permit longer periods of operation of suchengines without the necessity oi major overhauls heretofore occasionedby stuck piston rings.

It should be noted that stabilizing agents which are effective at lowtemperatures to impart increased stability to hydrocarbon oils, or whichare effective at temperatures even as high as 200.

stabilizer at atmospheric temperatures, or even temperatures as high as200 to 300 F., gives no adequate basis for predicting the action of thesame stabilizing agent at materially higher temperatures and under moresevere operating conditions. The disclosures in the prior art relativeto such stabilizers therefore cannot serve as a guide for one seekingstabilizing agents or oxidation inhibitors efiective at highertemperature levels. The phenomena. involved are catalytic in nature,arehighly empirical, and require extensive experimentation to determinethe action of a or 250 F., areoften inefl'ective under the more giventype of addition agent.

The present invention involves the discovery that dispersion of alkalineearth metal salts of sulfur-containing substituted acid of phosphorus inhydrocarbon oils, such as mineral lubricating oil, imparts new,unpredictable and highly desirable properties to the composition. Thesenew properties render the compounded oil particularly useful for variouspurposes. Although increased resistance to deterioration at hightemperature levels comprises one 01' the principal advantages of thecompounded oil of this invention, it is to be understood that theinvention is not limited to this feature and that difierent compounds ofthe general type involved herein vary in their degree of effectiveness.In general, however, it has been discovered that the new compositionsherein disclosed are. more stable to heat than is a hydrocarbon oil withwhich the compositions are compounded. The new compositions of thisinvention are therefore useful where resistance to deterioration by heatis important. An example of such utility other than as a lubricating oilcomprises use as a heat transfer fluid where it may be desirable toinhibit or prevent the formation of a deposit on the metal surfaces fromor to which heat is beingconveyed. Likewise, the increased resistance tooxidation imparted to the oil by the compounds of this invention willfind various applications as, for instance, in insulating, switch ortransformer oils.

It has also been discovered that calcium salts of sulfur-containingsubstituted phosphoric acids, in particular, have a combination ofproperties heretofore unknown and particularly desirable in compoundedlubricating oils, namely, the ability to inhibit oxidation and impart tolubricating oils increased resistance to deterioration by heat, the

' ability to inhibit piston ring sticking, freedom from the productionof increased wear on cylinder walls and piston rings as compared withuncompounded mineral oils, not only low corrosivity as respects thechemical action or the compounded 2 2,252,985 n on bearing metals, suchas cadmium-silver ing at least twelve carbon atoms in the molecule.

and copper-lead alloys, but the capacity to actually'lnhibit thecorrosive action of highly P oils on these bearing metals, and thecapacity to inhibit piston ring sticking and ring slot carbon formationin parafllnic lubricating Oils of the Pennsylvania type. Althoughvarious compounding agents are known which are capable of inhibitingpiston ringsticking, the discovery of specific agents capable ofimparting the above combination of properties to hydrocarbon oilsrepresents an unobvious and important contribution.

Alkaline earth metal salts of sulfur-containing substituted acids ofphosphorus which may be added to hydrocarbon lubricating oils to providea new composition of matter of the type herein involved comprisecompounds which may be represented by the general formula:

where M is an alkaline earth metal selected from Group II of MendelyeevsPeriodic Table of the Elements. Examples of such metals are calcium,strontium and barium. For the purposes of this invention, in its broaderaspects, magne'sium may also be classified as an alkaline earth metal.In the above formula R may be alkyl, aryl, alkaryl, aralkyl, or cyclicnon-benzenoid groups; X and Y each are either sulfur or oxygen andsulfur; H is hydrogen; P is phosphorus; a, b, d and 2 represent smallwhole, numbers, and c may be zero or a small whole number.

The salts of this invention are preferably formed from substituted acidsof pentavalent phosphorus of one or more of the following type formulae:

where R and R may be alkyl, aryl, alkaryl, aralkyl, or cyclicnon-benzenoid groups. Substituted acids containing at leastapproximately twelve carbon atoms are preferred. Examples di-ester ofmono-thiophosphoric acid of preferred type acids are alkyl or alkarylsulfur-containing substituted phosphoric acids hav- However, it is to beunderstood that the broader aspects of the invention include other typesof sulfur-containing substituted acids of phosphorus containing morethan twelve carbon atoms. Additional examples of such acids which may beused in forming the alkaline earth metal salts of the present inventionare as follows:

mono-thioester o! phospbonic acid mono-ester oi iritblcphosphonic acidmono-thioesier oi trithiophosphonic acid alkyl, aryl, alkaryl, aralkyl,or cyclic non-benzenoid groups.

In general, alkaline earth metal salts of sulfur-containing substitutedderivatives of acids of phosphorus, such as phosphorous acid, HaPO-s;hypophosphoric acid, HzPOa; ortho- Dhosphoric acid, H3PO4;pyrophosphorlc acid, HiPzO-z; monothiophosphoric acid. HzPSOs;dithiophosphoric acid, HaPSaOa; trithiophosphoric acid, HaPSaO;tetra-thiophosphorlc acid; H.1PS4; thiopyrophosphoric acid, HJaSw; andtrithiopyrophosphorlc acid, H4PaSaO4, fall within the broadest aspectsof the invention. By substituted acids" or substituted derivatives ofphosphorus, whenever used herein, it is intended to designate acids ofphosphorus containing an organic group of the type previously listed.The organic group may be either directly attached to the phosphorus atomof'the compound or attached thereto through an intervening atom such asoxygen or sulfur. The term sulfurcontainlng" is intended to designatecompounds in which either the original acid of phosphorus or the organicderivative thereof contains sulfur.

The preferred acids are sulfur-containing substituted acids ofpentavalent phosphorus and the preferred salts comprise calcium salts ofsuch acids. Examples of preferred salts are calcium cetyl thiophosphate,calcium cetyl phenyl thiophosphate, and a calcium salt of the acidphosphoric acid ester of di-(p-hydroxy phenyl) sulfide. Salts such ascalcium thiccresyl phosphate are less effective than the previouslyrecited compounds but improve various properties of the oil.particularly its resistance to oxidation. U

Additional examples of salts within'the scope of the invention arecalcium lauryl thiophosphate, calcium octadecyl thiophosphate, calciumspermol thiophosphate, calcium oleyl thiophosphate, calcium spermenylthiophosphate, calcium di-(amyl phenyl) thiophosphate, calciumnaphthenyl thiophosphate, calcium di-cyclohexanyl thiophosphate, calciumtetra-chloro-octadecyl thiophosphate, calcium di-(6-chloro. 2- phenylphenyl) thiophosphate, calcium di-(3 methyl, 4-chloro-phenyl)thioph'osphate. barium lauryl' thiophosphate, barium octadecylthicphosphate, barium spermol thiophosphate, barium oleyl thiophosphate,barium spermenyl thiophosphate, barium di-(amyl phenyl) thiophosphate,barium naphthenyl thiophosphate,

instance, the calcium salt may be manufactured barium dl-cyclohexanylthiophosphate; barium. tetra-chloro-octadecyl vthlophosphate, bariumdi-(B-chloro, 2-phenyl phenyl) thiophosphate, and barium di-(3-methyl, 4-chloro-phenyl) thiophosphate. a

The sulfur-containing substituted acids of phosphorus utilized forpreparing the alkaline earth salts of this invention may contain organicsubstituents other than pure hydrocarbon groups. The organic radical inthe acid of phosphorus may comprise, in addition to the carbon andhydrogen, substltuents such as the halogens, chlorine or bromine,hydroxy, suii'hydryl and similar groups. Likewise, the sulfurin thesulfur-containing atom need not necessarily be directly attached to thephosphorus atom. An acid which illustrates these types of compoundscomprises the phosphoric. acid ester of di-(phydroxy phenyl) sulfide.

The acids of phosphorus utilized in the present composition may beprepared by various methods. For example, a mixture of ahigher alcoholand phosphorus pentasulflde, a mercaptan and phosphorus pentoxide, amercaptan and phosphorus pentasulfide or a three-component mixture, suchas a mercaptan, phosphorus pentoxide by precipitation as follows: Waterand caustic potash are charged to a mixer and heated to a temperature of180 F. The acid is added, thereby forming an a1 1 salt. An aqueouscalcium chlor'de solution incorporated with violent agita ion duringprecipitation to prevent inclusion of the potassium salt. Theprecipitated curd is washed free of inorganic salts with hotiresh water.Mineral oil is then added and the solution is dehydrated 'as by heatingto a temperature of 300-330 F. The concentrated oil solution so obtainedmay conveniently be ,used for mixing or blending with other oils toprepare the completed product.

The alkaIine earth salts may also be prepared in the non-aqueousenvironment by the reaction of a metal carbide with the free substitutedacid.

For example, calcium carbide may be reacted 20 with free cetylthiophosphoric acid to yield acetylene and anhydrous calcium cetylthiophosphate.

By way of illustration and to demonstrate th unusual propertiespossessed by the compounded oils of this invention, test data are givenin Table I:

Table I Oxidator P t test; c.c. tHoursI ercen oxygen 0 stic CompoundMethod of manufacture of acid salt absorbed piston in 2.5 rings 1 hoursCOMPOUNDED IN ACID REFINED WESTERN OIL S. A. E.

Mineral nil 0 324 Calcium phosphate of p-hydroxydxp-Hydro y lpnylsulflde and zot 1 76 phenylsulfide. fphospholeum. Calcium thiocresylhos hate" Tluoeresol and P20t+phosphoieum 1 calcliaum cetylthiop ospate... Cetyila1cohol+P S 1 0 0 .05 Calcium cetyiphenylthiophosphate...Cety1phenol+PzS5 1 Calcium thiocresyithiophosphate.--. ThrocresoH-PzS; 1

COMPOUNDED IN PENNSYLVANIA OIL S. A. E. 30

Mineral oil 0 302 Calcgum cetylphenylthiophosphate... Cety lphenol+P2Sr1 13 n o 0 .5 165 Calcium cetylphcnylthiophosphate+ do .5+.25 1;

calcium cetylphenate. Calcium thiocresy1thioph0Sphate Thiocre'sol+PSt 11 88 and pyrophosphoric acid, may be directly fused in proportions togive acid esters. The reaction by which the substituted phosphoric acidis formed in the last mentioned three-component mixture is believed tobe represented by the following equations:

the alkali metal salt of the above acid may be dissolvedin aqueoussolution and the alkaline earth metal salt precipitated therefrom. For

It will be observed that all of the compounding 1 try, 1936, vol. 28,page 26, and was carried out in the present examples at 340 E, whichrepresents" very severe conditions. t

In the piston ring sticking tests a single cylin- -der, 2%" bore, 2stroke, Lauson gasoline engine was operated under extremely severeconditions for the purpose of developing fully piston ring sticking andpiston gumming tendencies under circumstances simulating severeoperating conditions encountered in the field. Operation of the motorduring test was continuous at 1600 R. P. M. except for periodicshut-downs at fifteen-hour intervals for inspection. The jackettemperature was maintained at'approximately 375 F. and the sump oiltemperature at approximately 220 F. during the test.

' The compounding agents of this invention are outstanding in that theyare more eflective to inhibit piston ring sticking in Pennsylvania typeoils than are any compounds heretofore found.

pounding agents are also effective to inhibit the corrosive action orparaflinic oils on'bearing metals, such as copper-lead or cadmium-silveralloys. Corrosion data, together with data on the increase in viscosityof the oil and A. S. T. M. insolubles, are given in Table II:

'- Table II Calcium Calcium Y Mineral cetylt g f}; oil Penn. henylf s.A. Lao tfiiophoscetylphenate Percent salt 1 .6+.25 Stri corrosiontest:

g.loss72hr.- Cu-Pb 19.4 +1 5.0 Cd- 0.1 0.1 as Percent increase inviscostyat 00 F 1o 0 1o Ins. in A.S.T.M. naphtha,

.M 12 o a a The above corrosion tests were carried out in the followingmanner: Glass tubes 2 inches in diameter and 20 inches long wereimmersed in an oil bath, the temperature of which was automaticallycontrolled to within 21 F. of the test temperature, which was 300 F.Approximately the oils; in most cases the copper-lead and cadmium-silverbearing alloys were tested simultaneously in the same sample 01' oil.The weight loss of each strip was recorded. Before weighing, each stripwas washed in petroleum ether and carefully wiped with a soft cottoncloth. The duration of the test was '12 hours.

The compounding agents herein disclosed may have one or more advantages,depending upon the particular compound selected. the proportionutilized, and the environment which the lubricating oil is to encounter.It should be observed, for example, that even though a compounded oilmay be somewhat corrosive to copper-lead or cadmium-silver bearingmetals, Babbitt bearings are little, it at all, affected by suchcorrosive action. .Hence, compounded oils which may not be particularlydesirable for lubrication of copper lead or cadmium-silver bearings maybe highly useful and extremelyadvantageous in conjunction withtheoperation or internal combustion engines having bearings of Babbittor other corrosion-resistant bearing metals. The present invention inits' broader aspects is therefore not limited to a particular compoundhaving 'all or the greatest number or advantages, but

embraces various oi the less advantageous addition agents which willfind utility in particular applications where all the possibleimprovement in properties may not be required or where the standard orperformance may not be so high.

Present experience indicates that where the properties desired involvethe ability to stabilize lubricating oils under severe operatingconditions such as those encountered in the lubrication of pistons andpistonrings 01. internal combustion;- englnes of the Diesel type,alkaline earth salts of sulfur-containing substituted acids ofpentavalent phosphorus containing more than twelve carbon atoms in themolecule and preferably containing an alkyl or alkaryl substituentshould be utilized.

p V 9,952,085 a v As has been pointed out hereinbeiore, the comi Amoderately acidreflned Watern'naphthenic function more efl'icicntly insuch a base oil than in a highly parailinic oil stock or a highlyrefined Western oil. However, it is to be understood that the inventionis not limited to such a base stock since various 0! the presentcompounds, particularly the calcium salts, are more eflective ininhibiting oxidation and corrosion effects in parafllnic oilstocksthanare any compounds so iartested.

The proportion of the alkaline earth .metal salts of substituted acidsof phosphorus added to mineral lubricating oils may vary widely dependmgon the uses involved and the properties desired. As li ttle as 0.05% byweight of the compound gives measurable' improvements, particularly asrespects inhibiting oxidation and color stability of the compounded oil.From approximately 0.25 to approximately 2% of the compound may be addedto lubricants where increased stability, in internal combustion enginesand resistance to piston ring sticking comprise the principal propertiesdesired. Solutions containing more than 2% 01' the compounds in mineraloil may be utilized for the purpose of preparing' lubricating greasesand concentrates capable of dilution with lubricating oils and the like.Such higher concentrations comprise a convenient method of handling thecompounds and may be used as addition agents for lubricants in generalas well as for other purposes.

The alkaline'earth metal salts of this invention may be added tohydrocarbon oils containing other compounding ingredients sucii as pourpoint depressors, oiliness agents, extreme pressure addition agents,blooming agents, compounds for enhancing the viscosity index of thehydrocarbon oil, corrosion inhibitors and the like. The invention in its"broader aspects embraces mineral hydrocarbon oils containing, inaddition to metal salts of the substituted acids of phosphorus,thickening agents and/or metal soaps in proportions or in amountsinsuflicient to form greases, as in the case of mineral castor machineoils or other compounded liquid lubricants.

The compounds of this invention may be added to oils other thanhydrocarbon lubricating oils, for example, fueloils, non-dryingvegetable or animal oils, or synthetic oils, such as olefin polymers andhydrogenated oleiln polymers.

While the character of the invention has been described in detail andnumerous examples of the composition given, this has been done by way ofillustration only andwith the intention that no limitation should beimposed on the invention thereby. It will be apparent to those skilledin the art that numerous modifications and variations of theillustrative examples may be effected in the practice 01' the inventionwhich is of the scope of the claims appended hereto.

We claim:

1. A composition of matter comprising a hydrocarbon oil subject todeterioration at elevated temperature, and an alkaline earth metal saltof a sulfur-containing substituted acid of phosphorus having an organicsubstituent therein, said salt being present in. an amount sumcientsubstantially to inhibit said deterioration.

2. A composition of matter comprisinga hydrocarbon oil subject todeterioration at elevated temperature, and a calcium salt 01' asulfurcontaining substituted acid of phosphorus having an organicsubstituent therein, said salt being present in an amount sufficientsubstantially to inhibit said deterioration.

3. A composition of matter comprising a hydrocarbon oil subject todeterioration at elevated temperature, and a barium salt of asulfur-containing substituted acid of phosphorus having an v containingsubstituted acid of phosphorus having an organic substituent therein,said salt being present in an amount suflicient substantially to inhibitsaid deterioration.

5. A composition of matter comprising a hydrocarbon oil subject todeterioration at elevated temperature, and an alkaline earth metal saltof a sulfur-containing substituted acid of pentavalent phosphorus havingan organic substituent therein said salt being present in an amountsuflicient substantially to inhibit said deterioration.

6. A composition of matter comprising a hydrocarbon oil subject todeterioration at elevated temperature, and a calcium salt of asulfur-containing substituted acid of pentavalent phosphorus having anorganic substituent therein, said salt being present in an amountsuflicient substantially to inhibit said deterioration. 'l. Acomposition of matter comprising a hydrocarbon salt subject todeterioration at elevated temperature, and a barium salt of asulfur-containing substituted acid of pentavalent phosphorus having anorganic substituent therein, said salt being present in an amountsuflicient substantially to inhibit said determination.

8. Awomposition of matter comprising a hydrocarbon oil subject todeterioration at elevated temperature, and a magnesium salt of asulfurcontaining substituted acid of pentavalent phosphorus having anorganic substituent therein, said salt being present in an amountsuflicient substantially to inhibit said deterioration.

9. A stabilized liquid. lubricant comprising a lubricating oil and analkaline earth metal salt of a sulfur-containing substituted acid ofphosphorus having an organic substituent therein, said salt beingpresent in an amount .suflicient to stabilize said oil againstdeterioration during use.

10. A stabilized liquid lubricant comprising a lubricating oil and analkaline earth metal salt of a sulfur-containing substituted acid ofpentavalent phosphorus having an organic substituent therein, said saltbeing present in an amount sumcient substantially to stabilize said oilagainst deterioration during use.

11. A composition of matter comprising a hydrocarbon oil subject todeterioration in the presence of oxygen, and an alkaline earth metalsalt of a 'thio-ester of phosphoric acid, said salt being present in anamount suflicient substandrocarbon oil subject to deterioration in thepresence of oxygen, and a barium salt or a thio-ester .of phosphoricacid, said salt being present in an amount sufllcient substantially toinhibit said deterioration. Y i

14;. A composition of matter comprising a hydrocarbon oil subject todeterioration in the pres- 4 ence of oxygen, and a magnesium salt of athinester of phosphoric acid, said salt being present in an amountsumcient substantially to inhibit said deterioration.

15. A composition of matter comprising a hydrocarbon oil subject todeterioration in the presence of oxygen, and an alkaline earth metalsalt of an ester of a thiophosphorie acid, said salt being present in anamount sufilcient substantially to inhibit said deterioration.

16. A" composition of matter comprising a hydrocarbon oil subject todeterioration in the presence of oxygen. and a calcium salt. of an esterof a 'thiophosphorie acid, said salt being present in an amountsufficient substantially to inhibit said deterioration.

1'7. A composition of matter comprising a hydrocarbon oil subject todeterioration in the presence ofoxygemand a barium salt of an ester of athiophosphoric acid,'s'aid salt being present in an amount sufiicientsubstantially to inhibit said deterioration.

18. A composition of matter comprising a hydrocarbon oil subject todeterioration in',the presence of oxygen, and a magnesium salt of anester of a thiophosphoric acid, said salt being present in an amountsuflicient substantially to inhibit said deterioration.

19. A stabilized liquid lubricant'comprising a paraflinic lubricatingoil and more than approximately 0.05% by weight based on the oil of analkaline earth metal salt of a sulfur-containing substituted acid ofphosphorus having an organic substituent therein.

20. A stabilized liquid lubricant comprising a paraifinic lubricatingoil and more than approximately 0.05% by weight based on the 'oil of acalcium salt of a sulfur-containing substituted acid of phosphorushaving an organic substituent therein. I

21. A compounded lubricant comprising a inbricating oil and fromapproximately 0.05% to approximately 2% by weight based on the oil of analkaline earth metal salt of a sulfur-containing substituted acid ofpentavalent phosphorus having more than approximately twelve carbonatoms in the molecule.

22. A compounded lubricant comprising 'a lubricating oil and fromapproximately 0.05% to approximately 2% by weight based on the oil of acalcium salt of a sulfur-containing substituted acid of pentavalentphosphorus having more than approximately twelve carbon atoms in themolecule.

23. A compounded lubricant comprising alubricating oil and 'fromapproximately 0.05% to approximately 2% by weight based on the oil of abarium salt of a sulfur-containing substituted acid of pentavalentphosphorus having more than approximately twelve .carbon atoms in themolecule 24. A compounded lubricant comprising a lubricating oil andfrom approximately 0.05% to approximately 2% by weight based on the oilof a magnesium salt of a sulfur-containing sub CERTIFICATE 013 common0N.

Patent-"K0. 2,252,985. August 19 191 1. 1 Y I Jon 1. mmnmnn, ET AL.

It is hereby certified that error appear; in the printed specificationof the above mmbered patent requiring correction as follows: Page5,,first column, line 514., 0111117, for the word "salt" read --oil-;line 59, sane. claim, for "determination" read. --deterioration--; line51, claim 9, after 'sufficiefit" insert -subatentially--; and that thesaid Letters Patent ahofild be read with this correction therein thatthe some may conform to the record of the case in the Patent Office.

Signed and sealed this 28th da of October, 1,. D 1911.1.

Henry Van Arsdale, H (Seal) Acting Conmis sioner of Patents.-

DISCLAIMER 2,252,985.-John T. Rmhmwd and Robert J. Miller, Berkeley,Calif. CoMPoUNbEo OIL. Patent dated August 19, 1941. Disclaimer filedMay 10, 1944, by v the assignee, Standard Oil Company of California. 7Hereby enters this disclaimer to claims 1,- 2, 4, 5, 6, 8, 9, 10, 11,12, 14, 15, 16, 18, and 24 of said patent. I

[Ofiieial Gazette Jane 6, 1,944.]

CER'iPIFICATE 0F commcnonl Patent R0. 2, 252, 985. w

August 19, 19!;1. Jean *1. RUTHERFORD, ET AL. V

It is hereby certified that error appeare in the printed specificationof the above numbered patent requiring correction as follows: Page 5,first line 31;, clum'r, for the word "salt" read -oi1--; line 59, same."determinetion" read -deterioration-; line 51, claim 9, after Patentcolumn,

claim, for "gufficiexit" insert --substantially-; and that the saidLetters shoizld be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 28th day of October, A. D 191:1.

Henry Van Arsdale,

(s l) Acting Commissioner of Patents;

DISCLAIMER 2,252,985.J0hn T. Rutherford and Robert J. Miller, Berkeley,Calif. COMPOUNDED OIL. Patent dated August 19, 1941. Disclaimer filedMay 10, 1944, by the assignee, Standard Oil Company of California. 7Hereby enters this disclaimer to claims 1, 2, 4, 5, 6, 8, 9, 10, 11, 12,14, 15, 16, 18, and 24 of said patent.

[Ojfic'ial Gazette June 6', 1944.]

